The invention relates to a drilling and milling mechanism.
In a known drilling and milling mechanism (EP 0 368 996 B1) the clamping axis about which the workpiece support is adapted to be driven in rotation is oriented horizontally in a position determined by the arrangement of the machine bed and parallel to the longitudinal direction thereof. Accordingly, the material rod, the axis of which coincides with the clamping axis, always is oriented horizontally, parallel to the longitudinal direction of the machine bed. The tool spindle carried by the movable column is disposed perpendicularly and can be equipped successively with a plurality of tools, such as drilling or milling cutters for machining a workpiece which is embodied by a front end portion of a rod of material. The movable column is furnished, in addition, with a severing unit which operates independently of the tool spindle and serves to cut off the workpiece having been machined. A carriage which is independent of the movable column is displaceable in longitudinal direction of the machine bed, and a gripping and pivoting unit is mounted on the carriage. The gripping and pivoting unit comprises a chuck which can be utilized as brackets while the workpiece, still integral with the material rod, is being machined and which completely takes over the workpiece when it has been separated from the material rod so that its back can be machined by one or more tools arranged in consecutive order on the tool spindle. The chuck is pivotable about an axis which, for being normal to the clamping axis of the workpiece support and to the spindle axis, extends horizontally. For this reason even inclined cuts or bores, for instance, may be formed in the workpiece which is clamped in the chuck of the gripping and pivoting unit. However, once the workpiece has been transferred from the clamping means at the workpiece support to the chuck of the gripping and pivoting unit, the precision in machining achievable, generally, is not quite as high as before the transfer because inaccuracies may slip in during each workpiece transfer.
It is, therefore, an object of the invention to facilitate especially versatile machining of each respective front workpiece still linked to the material rod, when rods of material are processed in a drilling and milling mechanism while, at the same time, increasing the machining accuracy.